Russell Verney, Perot's spokesman, said the Texas billionaire decided against running in the primary because he had no intention of actually competing for the White House in the fall against Republican George W. Bush and Democrat Al Gore.

A daylong series of meetings at Perot's office in Dallas included "intense pressure" on Perot to put his name on the ballot in an effort to stop Buchanan, Verney said. Perot resisted such a "negative reason" for running and also felt it would be unethical to seek the nomination but not really run, Verney said.

Besides, Perot, who turned 70 on Tuesday, would be on only about half the states' ballots in November.

"When you're trying to create a new political party which sets the highest ethical standard, you cannot try to further that goal by unethical actions," Verney said.

Buchanan praised the decision in a statement and said Perot had an open invitation to speak at the party's August convention.

"I have great respect for Ross Perot. He is the founder and father of this party," Buchanan said. "Without Ross Perot, there would be no Reform Party, no third choice and there would be no great third-party movement in the 1990s. I wish him well."

Though Perot declined to make a statement on Friday, he is said to be dissatisfied with Buchanan's candidacy. Verney said Perot might make a public statement about his feelings before the party's nominating convention, which will be Aug. 10-13 in Long Beach, Calif.

Perot's supporters, meanwhile, will lobby the party's nominations committee to make "No Endorsement" an option on the primary ballot in order to allow Buchanan opponents to protest his candidacy, Verney said.

Perot's decision comes after longtime supporters, led by Ira Goodman of New Jersey, collected what they said were enough signatures in 18 states to meet the party's rules for putting a candidate on the ballot. Perot had until midnight Friday to accept a spot on the ballot in writing.

It would have been his third presidential campaign on the ticket of the party he founded, after finishing with 19 percent of the vote in 1992 and 8.5 percent in 1996.

He burst onto the political scene in 1992, spending more than $60 million of his money. Four years later, he spent most of the $29 million he received in federal funds on television time and an abbreviated campaign.